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(energetic music)

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(typing)

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In this video, we're going to download the

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YouTube player library and add it to a project

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that we're also going to create.

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So, with Android Studio loaded,

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we're going to create this new project by clicking on,

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Start a New Android Studio Project,

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and we'll call this one YouTube player.

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Now, notice that I've used a lower case T

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in the word YouTube.

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For the library that we're going to be using,

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that has a capital T throughout.

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And what I suggest you do for the company domain

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is do something a little bit different.

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Now, in my case I'm going to use

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learnprogramming.academy for the company domain.

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But the reason we want to do something different

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is because we need to get an API key from Google

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and it's tied to the package name for the app.

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Now, I'm going to show you how to get the API key

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in another video.

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And that key's used by Google to track usage of your app.

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And that allows them to charge you,

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but don't worry you get plenty of free use.

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So that won't be a problem for this app.

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But if every student used the same key,

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then without the 40,000 students that signed up

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to my previous version of this course,

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it may well be a problem.

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So don't worry about being charged though,

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you have to enable billing in the developer console

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before Google will charge you.

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And you'd have to use the app continuously

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on loads of devices all day to exceed

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the generous daily limit that they actually give you anyway.

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And again, if you haven't enabled billing,

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you won't get charged.

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And it'll actually stop working until the next day.

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So, no matter what if you don't enable billing

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you won't get charged anything,

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if you do happen to manage to go over the usage allowance.

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So for this company domain,

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I'm going to stick to using learnprogramming.academy.

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But if you've got your own domain name,

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I suggest you use that.

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Otherwise use something like yourname.example.org,

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something that will be unique to you.

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And probably a good idea to run your first and last name

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together, like Tim Buchalka.example.org for example,

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or the other way around.

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Just try to make sure you enter something unique there.

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Alright, so you know the drill

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with the Kotlin support pass by now,

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so tick it if you want Kotlin code or un-tick it for Java.

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And I'm going to click on Next now,

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and in fact you know the whole process pretty much now,

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so in future videos we're going to be starting

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with the project already created and open and I'll just give

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you the project name and template to choose.

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Alright, so I'm going to choose API 17 here as before,

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go to Next.

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I'm going to select Empty Project, Empty Activity,

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click on Next.

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I'm going to leave the default,

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for the activity name and the layout name,

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so that Android Studio creates the activity for us,

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and also creates a layout and

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I'm going to click on the Generate Layout File check box

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as well as the Backwards Compatibility one

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and click on Finish.

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Alright now while that's getting setup,

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what we need to do is go ahead and download the library

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that we're going to be using for this project.

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So let's go ahead and do that.

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So I'm going to open a browser.

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Going to paste in the URL.

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And again what we're doing here, is what we need to do,

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is integrate the YouTube API into our app.

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And we have to download the library file from the

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Google YouTube site which I've gone to now.

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And in case you're wondering, API stands for,

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Application Programme Interface.

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An API provides functions or classes for performing

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a certain task or one task or another,

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in this case playing YouTube videos.

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Alright so pages you can see here contains

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a lot of information on using the Android YouTube API.

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There's also this "Reference" tab up here which you can

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check with all the documentation for the various classes.

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And as an exercise, perhaps once you've

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finished this app in this section of the course,

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you might want to come back and

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experiment with various other things.

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One example might be checking out this

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YouTube.ThumbnailLoader.

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So, have a play once you finish

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the app in this section of the course.

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And maybe modify it to add some more functionality.

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By the time we finish this app,

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you will understand how to do things like,

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launch a new activity when the user clicks a button,

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so that you can add more screens to the app if you want.

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So there's all this information available,

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which makes using the API a lot easier.

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But we need to download the library,

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so I'm going to click on "Guides" up here,

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the "Guides" tab to go back.

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Now just down the page here,

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is a link to the download page, this one here.

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There's also a link over here in the left-hand side.

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But I'm showing you this one for a reason.

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And it's saying you need to have version 4.2.16 or higher

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of the YouTube app installed on your device,

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to be able to use this API.

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Now previously, I had to suggest that you use a physical

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device to test this app on, however,

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when the Android Oreo was released,

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Google also released emulators that can instal apps

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from the Google Play Store,

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so that limitations been removed.

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There's actually now two different types of emulators,

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but we'll be discussing the differences

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when we come to running this app.

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So for now, I'm going to click on the download link.

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That takes us to the download page.

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Now the version number while I'm recording this video,

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as you can see on the screen, is 1.2.2.

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And it doesn't seem to change very often.

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But if there happens to be a new version

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when you come to watch this, then that's fine.

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Just grab that current version and download it.

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So I'm going to click on download.

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And I'm going to save it to my downloads folder.

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Now we're going to find that downloaded file,

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and I'm going to double click it in my case to extract it.

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But if you're on Linux,

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you can right click and choose extract,

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and if you're on Windows you can do a similar thing,

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you can click on extract all.

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So basically,

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unzip the file and then go into the unzipped folder,

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there's a libs sub-folder,

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you want to click on that,

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then there's this YouTubeAndroidPlayerAPI.jar,

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so we're going to select that.

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In my case I'm going to select copy, so you'll do

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the equivalent if you're on Windows or on Linux.

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And then we want to swing back to our project

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in Android Studio.

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Now, generally speaking, keeping the project pane in

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Android view is more convenient but there are a

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few things that you can't do in Android View.

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One of these is copying external libraries into the project.

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That's because the libs folder, that we need,

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isn't available in Android view.

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So you can see up here there's no mechanism

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to get to the libs folder.

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So what I'm going to do,

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is switch into project view briefly

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using this drop-down up here.

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Select Project.

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Once I do that I can then click to open the project folders,

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click on app.

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We've now got this libs folder,

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and you can see at the moment that's empty.

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So I can right click the libs folder and I can select Paste.

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Now you can see that we've got a dialogue

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asking for confirmation of the copy.

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So make sure the directory it's copying the file into

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does say libs at the end.

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And you can see clearly here on my screen

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that it does say libs so we're in the right place,

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click Okay.

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Now if we expand by clicking on this little triangle,

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we can see that the YouTubeAndroidPlayerAPI.jar

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is now in the libs folder.

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With that done I'm going to go back now

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and switch it back to Android view.

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So now that we have copied the file into the libs folder,

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we need to tell Android Studio to use it in our project.

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Now one way to do that, is to add a reference to it

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in the build.gradle file.

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The things are changing at the moment,

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and you might still be working on the older version

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of Android Studio as well as this one.

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So I'm going to show you another way.

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So you can go into the File menu

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and click on Project Structure.

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Once you do that, in the left-hand side list here,

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select app from the Modules section down here.

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Then you want to come over here to the right,

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and click on the "Dependencies" tab.

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That lists all the dependencies for this project.

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Now, as you can see, we're using the app compat library

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and we're also using the constraint layout et cetera.

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Now if you're producing Kotlin code,

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you'll also see the standard Kotlin library in the list.

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You can see down here of got that showing as well.

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Now right at the top, usually it's at the top,

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there's a reference to *.jar files in the libs directory.

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Now that would automatically include any jar files

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that we place in the libs directory.

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And of course, we've actually done that at the moment.

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So there's really no need to do what we're about to do,

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and that's because our YouTube library will be

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automatically included in the project,

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because we put it into the libs folder.

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But I think it's useful to know how to add libraries,

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especially if you decide to keep the

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jar files in a different directory,

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so I'm going to go through that process anyway.

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So to add a jar file explicitly rather than relying

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on that catch-all include, you click on the green +.

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In my case it's down here, but it may be at the top right

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depending on what operating system you're running on.

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But click on the add anyway in any event.

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Once you do that, you get this little pop-up menu.

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And I want to click on and choose Jar dependency.

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Now once you do that, that pops up a file browser

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which lets us browse the directories in the project.

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Now the jar file has to be in the project somewhere,

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so on Linux though unfortunately,

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there's no ability to move back up to

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browse the entire hard disc.

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On my Mac though, I have to actually browse into

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the project directory and find libs.

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And you'll need to do a similar thing for Windows.

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So in my case I'm actually already there,

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I've already got the YouTube Player app libs folder,

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and you can see the YouTubePlayerAPI.jar there,

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so with YouTubeAndroidPlayerAPI.jar is actually there.

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I can just expand that out we can see the full file name.

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So do whatever you need to do to get that open,

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select the file then and click on Okay or Open,

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depending on what you're operating system shows.

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And you can see that that entries

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been added now to this screen.

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Now if you want you can remove this

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catch-all include entry up here at this point.

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You just click on it and use the red minus button,

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or in my case it's not red but it will be depending on

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your operating system it may be a different colour,

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and it may also be over here to the right.

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But in my case on the Mac it's down at the bottom.

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So if I clicked on that now,

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that would actually remove that entry.

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But there's no need to remove it because the library

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won't be included twice if you leave it in.

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Now if you're experimenting with different libraries or

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trying different versions,

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then you don't want everything included automatically.

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And this is how you'd prevent

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everything in libs from being added.

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So any of your libraries you add explicitly

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will appear in the project if you actually remove this line.

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But I'm going to leave it,

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so you can see it in the build.gradle file.

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So for that reason I'm just going to click Okay,

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because we're actually finished here now.

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You can see it's got a gradle project sequence in process,

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so Android Studio quickly realised there was a change

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and synced the project for us.

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Now in earlier version of this course,

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we added the library by modifying the build.gradle file.

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But the way we've just done it is safer because

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there's no chance of typing the file name incorrectly.

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It's useful though to be familiar with build.gradle though,

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so let's have a look in there to see what we've just done.

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Now confusingly with Android Studio projects,

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there's two build gradle files,

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one you should edit and one that you'll very rarely change.

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Now the one we want,

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I'm going to click on and expand this down here,

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the one we want is in the apps directory.

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This one appears lower in the tree,

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so you can see below the project YouTubePlayer.

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It's this one here, build.gradle module app.

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Because we know to be looking at the android view though,

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I'm not going to change the file name here.

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And if you go back now, have a look in project view again,

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you can see we've got this build.gradle and it's actually

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in the app path and there's also another build.gradle there.

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But if we go back now again,

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just to have a look in Android view,

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we've got all the gradle scripts are in the same place,

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but it still shows us the module app here.

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And this is the one we ultimately want to have a look at.

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I'm going to double click on that to open it.

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And just out of interest,

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if you accidentally open the wrong one,

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have a look at this other one.

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It actually makes a point of saying,

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"Do not place your application dependencies here;

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they belong in the individual module build.gradle files".

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That's really just a warning,

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to let you know or to remind you that perhaps you're looking

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00:11:42,286 --> 00:11:43,592
at the wrong build.gradle file.

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So I'm going to close that one down

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and leave our app one open.

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Now eventually you will get used to which ones which,

302
00:11:48,483 --> 00:11:51,003
but until then just open one and if you see that warning

303
00:11:51,003 --> 00:11:53,072
then close it and then open the other one.

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00:11:53,072 --> 00:11:55,411
So in this case we've now got the right one open.

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00:11:55,411 --> 00:11:57,912
So, this module build.gradle file has all sorts

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of information telling Android Studio,

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00:11:59,981 --> 00:12:01,861
or really the gradle build system,

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00:12:01,861 --> 00:12:04,150
how to build the file that's deployed

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00:12:04,150 --> 00:12:06,621
to our devices or emulators.

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So down at the bottom here inside the dependencies section,

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we can see the jar file that we added

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right on the last line sitting there now.

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Now we could have just typed that line in instead

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of going through the menu that we did earlier in the video.

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If you do type these entries in,

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it's really important that you get the case right.

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Now I mentioned at the start of the videos about the

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upper and the lower case T.

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You can see here that on the libs/YouTube,

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we've got a capital T there.

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If you use a lower case T in YouTube, for example,

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it won't work.

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Now if you're used to Windows,

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remember to put the slash rather than

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the backslash between libs in the jar file names.

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So don't use back backslashes in other words.

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So at the top of this dependencies section,

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is that catch-all entry I talked about to include

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all jar files from the libs directory.

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Now I didn't delete it there so you can see it in here,

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but I'm going to delete that entire line now.

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And move that up.

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Now it's usually a good idea to be explicit about

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what you want to do in programming rather

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than relying on default behaviour.

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And this is why I've specifically listed

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the YouTube Android Player API jar file.

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So I've deleted that implementation file tree line.

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Now it wouldn't hurt to leave it in,

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00:13:17,016 --> 00:13:19,168
the library wouldn't be included twice.

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But we're being explicit here and we're listing the jar file

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in it's own implementation statement anyway on line 34.

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Now with that said, there's no guarantee that Google won't

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remove that default inclusion of all jars in the

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00:13:31,067 --> 00:13:33,373
lib folder so it's really useful to know

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00:13:33,373 --> 00:13:34,843
what's going on here.

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00:13:34,843 --> 00:13:37,024
Now whenever you make a change to the build.gradle file

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you'll get a message at the top as you can see now,

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00:13:38,961 --> 00:13:40,902
telling you that the file's changed.

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And you need to click the Sync Now link,

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00:13:42,974 --> 00:13:44,632
but if you're making several changes,

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you can actually do all the changes first just make sure

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that you do the Sync Now or click the Sync Now

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by clicking the link once you've finished

355
00:13:52,304 --> 00:13:55,931
the changes or you'll find things won't work properly.

356
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So I'm going to click on Sync Now.

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Now there are a few more things to look at in this file.

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The first are that these dependencies over here

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00:14:02,912 --> 00:14:05,592
start with the word implementation.

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00:14:05,592 --> 00:14:08,071
Now in previous versions of Android Studio,

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00:14:08,071 --> 00:14:11,163
that used to say compile instead.

362
00:14:11,163 --> 00:14:13,568
And if you're working on an old version as well or more

363
00:14:13,568 --> 00:14:16,149
accurately if you're using an older version of gradle,

364
00:14:16,149 --> 00:14:19,250
then that will be compile instead of implementation.

365
00:14:19,250 --> 00:14:21,269
So watch out for that and use compile

366
00:14:21,269 --> 00:14:23,658
if you're working with the older versions.

367
00:14:23,658 --> 00:14:25,319
Now if you go through Android Studios menu

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00:14:25,319 --> 00:14:28,749
like we did first, it will use the correct key word.

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00:14:28,749 --> 00:14:30,328
Now the other thing that you may want to change

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00:14:30,328 --> 00:14:33,416
in here are the minSdk up here,

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00:14:33,416 --> 00:14:36,389
and the targetSdkVersion here at the top.

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Now these are the values we provided in the wizard when

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we originally created the project earlier in this video.

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Now if you change your mind,

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then this is the place to change them.

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00:14:45,450 --> 00:14:48,218
So more importantly if you open an old project,

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00:14:48,218 --> 00:14:50,330
and you want to convert it to target the latest version

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00:14:50,330 --> 00:14:53,559
of Android or maybe drop support for an old version,

379
00:14:53,559 --> 00:14:56,090
then you can change these settings in here.

380
00:14:56,090 --> 00:14:58,210
Remember that the minimum version now supported

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00:14:58,210 --> 00:15:01,069
is API 14, Ice Cream Sandwich.

382
00:15:01,069 --> 00:15:03,587
Now if you're converting an old Marshmallow or Nougat

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00:15:03,587 --> 00:15:06,229
project to Oreo then you'll also want to change

384
00:15:06,229 --> 00:15:10,576
the compile SDK version to 26 and the build tools version

385
00:15:10,576 --> 00:15:12,959
to the latest version of Oreo.

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00:15:12,959 --> 00:15:16,084
So as I record this it's 26.0.2.

387
00:15:16,084 --> 00:15:18,408
But have a look at any new project that you've created

388
00:15:18,408 --> 00:15:20,150
to get the correct version numbers.

389
00:15:20,150 --> 00:15:20,983
Assuming that you've installed

390
00:15:20,983 --> 00:15:23,576
all the latest updates of course.

391
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Now the last thing here is that it's possible that this

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00:15:26,650 --> 00:15:30,223
appcompat line is actually highlighted.

393
00:15:30,223 --> 00:15:31,181
Now what I'm going to do,

394
00:15:31,181 --> 00:15:33,207
is change this back just to show you what I mean here.

395
00:15:33,207 --> 00:15:34,894
I'm going to change this back to an older version,

396
00:15:34,894 --> 00:15:35,727
26.0.2.

397
00:15:38,847 --> 00:15:39,680
Now I'm going to show you what happens

398
00:15:39,680 --> 00:15:42,042
when there's a newer version available.

399
00:15:42,042 --> 00:15:44,693
Leave that a moment to sync.

400
00:15:44,693 --> 00:15:46,802
You'll notice now that we've got an older version here,

401
00:15:46,802 --> 00:15:48,322
that this is actually highlighted.

402
00:15:48,322 --> 00:15:49,983
And if I hover over that it actually says

403
00:15:49,983 --> 00:15:54,602
a newer version of the appcompat library is available.

404
00:15:54,602 --> 00:15:56,560
If I actually click on that,

405
00:15:56,560 --> 00:15:58,171
we get the light bulb over here,

406
00:15:58,171 --> 00:15:59,694
I can come down here and I can click on

407
00:15:59,694 --> 00:16:02,603
change to 26.1.0 and that number will

408
00:16:02,603 --> 00:16:06,105
be whatever the latest version is and that will update it.

409
00:16:06,105 --> 00:16:08,673
Then I'll need to come over here and click on Sync Now.

410
00:16:08,673 --> 00:16:12,097
So if you see any entries highlighted like that in yellow,

411
00:16:12,097 --> 00:16:13,805
that's the way to actually update them to make sure

412
00:16:13,805 --> 00:16:16,274
that you're running the latest version.

413
00:16:16,274 --> 00:16:18,995
And keep in mind that when you click on the Sync Now button,

414
00:16:18,995 --> 00:16:21,216
that will actually do any necessary downloads to get

415
00:16:21,216 --> 00:16:24,296
that latest version for you, pretty cool.

416
00:16:24,296 --> 00:16:26,245
Now I've already went ahead and actually clicked on that

417
00:16:26,245 --> 00:16:27,876
and actually updated it,

418
00:16:27,876 --> 00:16:30,805
but generally before you update there are implications

419
00:16:30,805 --> 00:16:32,715
and that's why Android Studio

420
00:16:32,715 --> 00:16:35,385
didn't just go ahead and upgrade it anyway.

421
00:16:35,385 --> 00:16:37,184
Now you'll find it does that for certain things,

422
00:16:37,184 --> 00:16:38,734
like the gradle.build system.

423
00:16:38,734 --> 00:16:42,225
It will prompt you but can update to gradle automatically.

424
00:16:42,225 --> 00:16:45,072
The reason for that is that only effects the build process

425
00:16:45,072 --> 00:16:47,908
it doesn't change what's compiled into your final app.

426
00:16:47,908 --> 00:16:51,047
But changing those library versions does change your app.

427
00:16:51,047 --> 00:16:53,396
So if your apps gone through final testing, for example,

428
00:16:53,396 --> 00:16:54,767
and it's ready for release,

429
00:16:54,767 --> 00:16:57,217
you can't suddenly go changing the library versions.

430
00:16:57,217 --> 00:16:59,985
If you do, the app will need full testing again.

431
00:16:59,985 --> 00:17:01,636
And the other thing to keep in mind is that sometimes

432
00:17:01,636 --> 00:17:04,065
new libraries do introduce bugs.

433
00:17:04,065 --> 00:17:07,023
They can also change the way your app works in subtle ways.

434
00:17:07,023 --> 00:17:09,531
So bear that in mind if you change any

435
00:17:09,531 --> 00:17:12,142
of these library versions your app will need testing again

436
00:17:12,142 --> 00:17:13,761
before you release it.

437
00:17:13,761 --> 00:17:16,080
Now while you're working through the examples in this course

438
00:17:16,080 --> 00:17:18,950
I recommend that you do use the latest version of

439
00:17:18,950 --> 00:17:20,217
all the libraries though.

440
00:17:20,217 --> 00:17:21,933
And that's why I went ahead and clicked

441
00:17:21,933 --> 00:17:23,148
on the light bulb and I changed

442
00:17:23,148 --> 00:17:26,079
the appcompat version to 26.1.0.

443
00:17:26,079 --> 00:17:29,438
Which is the latest version currently existing.

444
00:17:29,438 --> 00:17:30,271
And then obviously,

445
00:17:30,271 --> 00:17:32,546
I went through and clicked on the Sync Now.

446
00:17:32,546 --> 00:17:34,298
Alright, we're going to be coming back to this file later

447
00:17:34,298 --> 00:17:36,546
to look at some of the other things in here.

448
00:17:36,546 --> 00:17:38,567
But for now though, that's the project set up

449
00:17:38,567 --> 00:17:40,823
so that we can use for YouTube API.

450
00:17:40,823 --> 00:17:43,784
So I'm going to go ahead and close the API app,

451
00:17:43,784 --> 00:17:45,607
the build.gradle file here.

452
00:17:45,607 --> 00:17:47,567
And I will finish off the video.

453
00:17:47,567 --> 00:17:48,938
In the next one we're going to start with

454
00:17:48,938 --> 00:17:52,476
creating a new activity to show those YouTube videos.

455
00:17:52,476 --> 00:17:54,095
So see you in the next video.